Thermodynamic study in aqueous solutions of weakly soluble ionic compounds.

Any investigation for a better knowledge of precipitation/dissolution problems necessitates the availability of all the beta formation constants of the uncharged soluble species (ion-pair). Several difficulties dealing with solubility measurements are briefly reviewed, especially related to phase structure variations, time-lag or supersaturation phenomena. Thanks to some thermodynamic considerations, the evolution of the uncharged soluble species with hydration and solid phase modifications can give a new explanation about the observed dispersion in literature values for some weakly soluble ionic compounds. When not given elsewhere, the evaluation of thermodynamic data of interest (formation constants, solubility product, etc.) is made possible according to given methods.